This invention relates to a container for water or ice in an ice bunker of an air cooling system, and more particularly to a closed variable-volume container which can be cooled to rapidly solidify water therein.
Water circulated and cooled over ice offers an economical means for space cooling. Cold-water is pumped from an ice bunker through an extended-surface coil. In the coil, the water absorbs heat from the air, which is blown across the coil. The warmed water than returns to the bunker, where its temperature is again reduced by the latent heat of fusion. Generally, a plurality of water-ice containers are housed within an ice bunker. When the containers are cooled to 7.degree. C., the water begins to solidify radially inwardly in the containers. Then, the external cooling temperature can be raised to 4.degree. C. at which temperature the water in the containers will continue to solidify. Because it is difficult for the outer layer of ice to conduct heat, in this icing process the external cooling temperature must be again lowered to 6.5.degree. C. so that the water in the containers can totally solidify. Using this rather low cooling temperature is time-consuming and power-consuming, resulting in high operating costs. When the water solidifies, its volume is enlarged. Whether the containers are filled with water or not, the solidification of the water in the containers will largely increase the pressure in the containers. Because conventional water-ice containers are of a fixed volume, they are easily damaged or deformed by repeated phase changes between water and ice.